New Zealand march on Twickenham today, and maybe the greatest mark of Graham Henry's success in moulding a side ready to win the World Cup is that if they lose it won't be the end of the world. Not many are expecting them to lose - and they should win - but if they suffer a rare defeat it won't really matter because their campaign is on track.

When the action starts in France next year, it will not be the first time New Zealand go into a World Cup as favourites. And each time in the past something has gone wrong, as people are never tired of reminding us. But there is a difference this time. I think there is a stronger fear and a real awareness of what it takes to win it.

In 1991, we were the champions going into it and that campaign was a bit of a disaster. Then in '95 we were able to claim that we were crocked by the mystery illness just before the final. In '99 we were up 20 points at half time in the semi-final. So we always had excuses not to look at the real issues. And then in 2003 that was when we had all had enough.

Henry will have had a good run-up to this World Cup. This is why today's game is so much more important for England than it is for the All Blacks. I see England as desperate to win and New Zealand continuing the preparation they've been doing for the past year or so.

What England need to start showing is what they want to do at the World Cup and how they're going to do it. It takes time. I've just taken over as Japan coach. If we qualify this month I've got a year to prepare. I wish I had three.

New Zealand, though, are well down the road. Henry has taken the kind of big policy decisions that Clive Woodward took for England last time around. He's got the team learning French. They've written their own haka. I think Clive called it the 'critical non-essentials', which is a beautiful phrase. These are the gambles that coaches take to give their side an edge. If Henry's going to have the All Blacks mingling fluently with the French next year, there will be some coaches who have their sides holed up in the mountains. And whoever wins will be able to say they got it right.

Some might say that the moment the All Blacks lost the last World Cup was when Tana Umaga was injured against my Italy side. There was no back-up to their skipper and leading centre, and this is the problem that Henry has addressed more than any other since he took over - the depth of the squad. I think he has done incredible work here, unlike a lot of people who think he has cheapened the All Black jersey with the way he has handed it around. Again, if he wins he'll be right, and if he loses he'll be pilloried.

The jersey is always sacred. It is untouchable because of the men that have been in it. But there have also been many who have been forgotten, and that's the fear any player feels when he pulls it on - not to be one of the forgotten ones. Henry hasn't just handed it round and then taken it back again. He has kept the same players involved by rotating them, so now he has a large, settled squad.

That doesn't belittle the jersey. When I got mine, Andy Haden said to me, 'So what? Now you've got to be a great one.' It's not so much about winning the jersey as making your mark in it.

I think the way Henry has assembled and rotated his squad puts fear into the opposition, which is what any coach wants - getting other coaches nervous about what they're going to do next. It creates what South Sea Islanders call mana, or prestige, around a team, just as England had in 2003 when they went down to 13 men but still beat the All Blacks in New Zealand. It helps to build up the legend.

Henry is doing that his own way by building so formidable a squad. It's a sensible policy. How would England have done last time if Jonny Wilkinson or Martin Johnson had gone down with injury?

So New Zealand are rightly favourites for next year. Although the French frighten me a wee bit. They're keeping very quiet, sitting back and letting the All Blacks have all the publicity. People tend to forget that we lost to France in 1986 before winning the World Cup 12 months later. I'd see them as the major risk.

For England, though, today is crucial. Andy Robinson (pictured) needs the next six months to be peaceful for him. He has a new coaching team to bed in, and if he loses badly this autumn there will be calls for his head. You really don't need that when you're trying to build for a World Cup. They need a win for their confidence.

But if they get one it will be no great drama for the All Blacks, because they're already locked on a well-planned course. The question is, are England? We'll know more by tonight.

John Kirwan, New Zealand World Cup winner in 1987 and the coach of Japan, will be writing on international rugby in The Observer